Body restraint systems including seat belts, lap belts, shoulder harnesses and the like have been credited with preventing injuries and saving numerous lives in vehicular accidents. The positive benefits obtained due to body restraints has been so recognized that, in the United States, the use of seat belts is mandated in all states.
Most conventional vehicle body restraint systems incorporate a belt that crosses in front of the lap and diagonally across the body of the vehicle operator or passenger. The belts are retained by latching mechanisms located within belt buckles wherein lock plates located at ends of the belts are inserted into the buckles to engage the latching mechanism. The buckles are in turn normally anchored to the vehicle frame.
Conventional seat belt systems generally utilize two types of latch release mechanisms to allow lock plates to be removed from buckle housings such that restrained occupants can exit the vehicle. A first type of latch release system includes a release button that is generally resiliently biased outwardly at an angle perpendicular to an axis or line of insertion of the lock plate into a buckle housing. To release the seat belt the occupant depresses the button with a force sufficient to overcome the bias. The button engages an actuator for the release mechanism, causing the release mechanism to operate and accordingly allows the lock plate to separate from the buckle. A second type of latch release system is an end release system and includes a lever or button for releasing the lock plate from the buckle housing. In the first instance the button is resiliently biased outwardly generally parallel to the line of insertion of the lock plate into the buckle housing. In the second instance the lever is pivotally mounted at an end of the buckle housing and biased such that the lever is held generally parallel to the lock plate. An occupant overcomes the bias to separate the belt from the buckle by depressing the button or pivoting the lever to engage the actuator and operate the latch release mechanism.
Latching mechanisms for vehicle body restraint systems are subject to unintentional release under certain conditions such as an accident, collision or rollover whereby a foreign object forcibly engages the latch release mechanism, compromising the effectiveness of the restraint system. Current seat belt latching mechanisms may include a simple bent tab to protect the latch release from intrusion by foreign objects. However, it is possible under certain conditions for a foreign object to avoid the tab and engage the latch release. In view of the foregoing, there remains a need to further improve upon the reliability and effectiveness of body restraint safety belt systems in vehicles to reduce the likelihood of unintentional release of latching mechanisms associated therewith by foreign objects during vehicle accidents, collisions and rollovers.